1. Field of the Invention
This invention relates generally to methods and apparatuses wherein material particles are caused to rapidly spin by interaction with intense beams of light. The interaction of the spinning particles with the energy gradient of the light beam or surrounding fluid causes the particles to orbit in a controlled manner leading to new apparatuses for guiding, trapping, concentrating, separating, injecting, and analyzing particles.
2. Description of Prior Art
The present invention encompasses an apparatus for the exploitation of an anomalous interaction (force) between the gradient field density and a particle spin induced by an intense beam of light. Such interaction can dominate the visual light pressure and cause micron to submicron sized particles to be attracted to a beam focus against the direction of the propagating vector of the light.
Such phenomena is observed at several different length and time scales in a number of different environments, i.e., micron-sized particles in air or other gasses, liquids, or other fluids, angstrom-sized particles in such varying environments is a fundamental feature of this invention. For example, for a micron-sized particle in a partially evacuated chamber, a laser may be used to induce a rapid spinning motion of a particle. In such high Reynolds' number fluid dynamical regime, the particle induces a turbulent vortex motion which interacts with the density gradient of the fluid caused by the localized heating of such fluid by the beam.
When such beam is focused down to a small spot size, for example 3-10 microns, the spinning particles are observed to spiral into the focal plane and become trapped by such spin-gradient force operating in both transverse directions and longitudinally. The present invention utilizes such spin-gradient interacting force to guide, trap, concentrate, and control particles. Secondary effects of such interaction may also be exploited. An example of such secondary effect is the separation of such particles according to their sizes and densities as they become trapped or repelled commensurate with the strength of an applied vacuum and strength of an applied energy source.
There is no prior art known to applicant in which such anomalous interaction (force) between the gradient of a field density and a particle spin induced by a beam of light is utilized to guide, trap, concentrate, separate, or control the motion of particles.